Surgical staple

ABSTRACT

A surgical staple, comprising a backspan, a first leg member extending from the backspan, a second leg member extending from the backspan, and at least one substantially continuous channel extending along at least one of an inner surface and an outer surface of the first leg member and the second leg member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/817,293 filed Jun. 17, 2010, which claims benefit of and priority toU.S. Provisional Application No. 61/235,155 filed Aug. 19, 2009, and thedisclosures of each of the above-identified applications are herebyincorporated by reference in their entirety.

BACKGROUND

Technical Field

The present disclosure relates to surgical fasteners and, moreparticularly, to surgical staples for use in surgical staplers havinganvil pockets for forming the staples.

Background of Related Art

Surgical stapling instruments have become critical to many life savingsurgical procedures. Surgical staples are usually mechanically insertedinto tissue with surgical stapling instruments such as those known asanastomosis devices, including gastrointestinal anastomosis devices andtransverse anastomosis devices.

In such devices, the staples are loaded in one or more elongated orannular rows into a cartridge. A mechanism for pushing, or driving thestapler is actuated to drive the staples through tissue toward adeforming anvil. At the conclusion of the driving operation, the legs ofeach staple are conventionally clamped or bent by the anvil to a closedconfiguration.

One type of conventional staple used with both gastrointestinalanastomosis and transverse anastomosis-type surgical stapling devices ismade of stainless steel or titanium. The undeformed staple is generallyU-shaped and includes a back span and two leg members dependingsubstantially perpendicularly from the back span. The staple penetratesthe tissue from one side to engage an anvil spaced apart and located atan opposing side of the tissue. The staple is bent by having the legsengage and follow an anvil to form a substantially B-shaped closedstaple. In this closed configuration, tissue is compressed between thelegs and backspan of the staple.

Conventional staples, such as staples having a substantially circularcross-section, require approximately the same amount of force to formthe staple into its final shape as is required to twist or malform thestaple. Such staples are susceptible to malformation during formation.In order to minimize the risk of staple malformation, it would bedesirable to have a staple that requires less amount of force to fire orproperly form the staple than the force needed to twist or malform thestaple.

SUMMARY

The present application provides in one aspect a surgical staplecomprising a backspan, a first leg member extending from the backspan, asecond leg member extending from the backspan, and at least onesubstantially continuous channel extending along at least one of aninner surface and an outer surface of the first leg member and thesecond leg member. The surgical staple can optionally be formed from amaterial selected from the group consisting of titanium and stainlesssteel.

In one embodiment, the at least one substantially continuous channelextends along the inner surface of the first and second leg members andbackspan of the surgical staple. In another embodiment, the at least onesubstantially continuous channel extends along the outer surface of thefirst and second leg members and backspan of the surgical staple.

In one embodiment, a transverse cross-section of each leg memberincludes a length and a height, wherein the length is greater than theheight.

The present application also provides in another aspect a staplecartridge for use with a surgical staple comprising a plurality ofsurgical staples in a spaced relation to each other, each of thesurgical staples including a backspan, a pair of deformable legsextending from the backspan and configured to come into contact withanvil pockets for formation of the staple, and at least onesubstantially continuous channel extending along at least one of aninner surface and an outer surface of the deformable legs.

In another aspect, the present application also provides a directionallybiased surgical staple comprising a backspan, a first leg memberextending from the backspan, a second leg member extending from thebackspan, and at least one substantially continuous channel extendingalong a surface of at least one of the backspan, the first leg memberand the second leg member. A transverse cross-section of each leg memberincludes a length and a height, the length being greater than theheight.

DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed surgical staple are disclosedherein with reference to the drawings, wherein:

FIG. 1 is a perspective view of a length of stock used to form a staplewith an internal channel or an external channel according to embodimentsof the present disclosure;

FIG. 2A is a perspective view of an unformed staple using the stock ofFIG. 1 having an internal channel;

FIG. 2B is a side view of the staple of FIG. 2A illustrating thestaple's leg members in a formed configuration through a layer oftissue;

FIG. 2C is a transverse cross-sectional view of the staple of FIGS. 2Aand 2B taken along plane 2C in FIG. 2A and along line 2C-2C in FIG. 2B;

FIG. 3A is a perspective view of an unformed staple of an alternateembodiment using the stock of FIG. 1 having an external channel;

FIG. 3B is a side view of the staple of FIG. 3A illustrating thestaple's leg members in a formed configuration and through a layer oftissue;

FIG. 3C is a transverse cross-sectional view of the staple of FIGS. 3Aand 3B taken along plane 3 c in FIG. 3A and along line 3 c-3 c in FIG.3B;

FIG. 4A is a perspective view of an unformed staple having two internalchannels in accordance with another embodiment of the presentdisclosure;

FIG. 4B is a side view of the staple of FIG. 4A illustrating thestaple's leg members in a formed configuration through a layer oftissue;

FIG. 4C is a transverse cross-sectional view of the staple of FIGS. 4Aand 4B taken along plane 4 c in FIG. 4A and along line 4 c-4 c in FIG.4B;

FIG. 5A is a perspective view of an unformed staple having two externalchannels in accordance with another alternate embodiment of the presentdisclosure;

FIG. 5B is a side view of the staple of FIG. 5A illustrating thestaple's leg members in a formed configuration and through a layer oftissue;

FIG. 5C is a transverse cross-sectional view of the staple of FIGS. 5Aand 5B taken along plane 5 c in FIG. 5A and along line 5 c-5 c in FIG.5B;

FIG. 6 is a transverse cross-sectional view of a staple having a rib inaccordance with an alternate embodiment of the present disclosure; and

FIG. 7 is a perspective view of a surgical stapler having a staplecartridge in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical staple are now describedin detail with reference to the drawings, in which like referencenumerals designate identical or corresponding elements in each of theseveral views. As used herein the term “distal” refers to that portionof the surgical staple, or component thereof, farther from the userwhile the term “proximal” refers to that portion of the surgical stapleor component thereof, closer to the user.

Referring initially to FIG. 1, a length of stock 50 is illustrated.Length of stock 50 may be any suitable material used to make surgicalstaples, such as stainless steel or titanium. It is envisioned thatlength of stock 50 is cut to an appropriate size and bent into asuitable staple shape, such as the shape shown in FIGS. 2A and 3A foruse as a surgical staple e.g., staple 200. Length of stock 50 is shownhaving a substantially oblate cross-section. A channel 210 is also shownextending continuously along length of stock 50.

A surgical staple, e.g., a directionally biased surgical staple, inaccordance with one embodiment of the present disclosure is shown inFIGS. 2A-2C. Specifically, FIGS. 2A-2C refer to surgical staple asreference numeral 200. As can be appreciated with respect to FIG. 1,surgical staples of the present disclosure are made from a length ofstock 50. That is, a length of stock 50 may be cut and bent to form astaple-like shape, such as the shape shown in FIG. 2A. Variousembodiments of the surgical staple are illustrated in the figures and itis envisioned that the configuration and/or shape of the staple may bevaried.

With reference to FIGS. 2A-2C, surgical staple 200 includes a backspan220, a first leg member 230, a second leg member 240 and a channel 210.First leg member 230 and second leg member 240 each extend from backspan220, preferably integrally therefrom, and preferably substantiallyperpendicular thereto, although they alternatively can extend atdifferent angles, e.g. converge or diverge with respect to the backspan.Note the staple legs of the other embodiments herein can also extendsubstantially perpendicular or at other angles to the backspan and thelegs are preferably formed integrally with the backspan. In theillustrated embodiment, channel 210 (e.g., a substantially continuouschannel 210) extends along an inner surface 250 of first leg member 230,backspan 220 and second leg member 240. As is discussed in more detailbelow, inclusion of channel 210 helps facilitate proper firing and/orformation of surgical staple 200 upon contact with an anvil portion suchas anvil portion 710 of a surgical stapler 700 (see FIG. 7).Additionally, and as discussed in more detail below, inclusion ofchannel 210 helps reduce the firing force necessary to properly form thestaple and also helps bias staple leg members 230, 240 to form in acertain direction.

With specific reference to FIG. 2B, surgical staple 200 is shown in adeformed orientation (configuration) and through a layer of tissue “t.”Specifically, first leg member 230 and second leg member 240 are shownin a deformed condition having a substantially curved shape and surgicalstaple 200 is shown in a B-like configuration.

Tissue penetrating portions 270 are shown formed adjacent a distal endof leg members 230, 240. Penetrating portions 270 may be of any knownconfiguration that facilitates entry of leg members 230, 240 into tissue“t” to be stapled. Tissue penetrating portions 270 are shown having achisel-like shape with points 272 adjacent inner facing sides of legmembers 230, 240.

With reference to FIGS. 3A-3C, another embodiment of the presentdisclosure is illustrated. Here, a surgical staple 300 includes abackspan 320, a first leg member 330, a second leg member 340 and achannel 310. First leg member 330 and second leg member 340 each extendfrom backspan 320, preferably substantially perpendicular thereto. Inthe illustrated embodiment, channel 310 (e.g., a substantiallycontinuous channel 310) extends along an outer surface 360 of first legmember 330, backspan 320 and second leg member 340. Inclusion of channel310 helps facilitate proper firing and/or formation of surgical staple300 upon contact with an anvil portion such as anvil portion 710 of asurgical stapler 700 (see FIG. 7). Additionally, inclusion of channel310 helps reduce the firing force necessary to properly form a stapleand also helps bias staple leg members 330, 340 to form in a certaindirection.

With specific reference to FIG. 3B, surgical staple 300 is shown in adeformed orientation (configuration) and through a layer of tissue “t.”Specifically, first leg member 330 and second leg member 340 are shownin a deformed condition having a substantially curved shape and surgicalstaple 300 is shown in a B-like configuration.

Tissue penetrating portions 370 are shown formed adjacent a distal endof leg members 330, 340. Penetrating portions 370 may be of any knownconfiguration that facilitates entry of leg members 330, 340 into tissue“t” to be stapled. Tissue penetrating portions 370 are shown having achisel-like shape with points 372 adjacent inner facing sides of legmembers 330, 340.

As can be appreciated, the transverse cross-sections of surgical staples200 and 300 are substantially identical (flipped vertically) and mayeach be formed from length of stock 50 of FIG. 1.

Another embodiment of the present disclosure is illustrated in FIGS.4A-4B. Here, a surgical staple 400 includes a backspan 420, a first legmember 430, a second leg member 440 and two channels 410 a, 410 b. Firstleg member 430 and second leg member 440 each extend from backspan 420.In the illustrated embodiment, channels 410 a, 410 b (e.g., asubstantially continuous channels 410 a, 410 b) extend along an innersurface 450 of first leg member 430, backspan 420 and second leg member440. Inclusion of channels 410 a, 410 b helps facilitate proper firingand/or formation of surgical staple 400 upon contact with an anvilportion such as anvil portion 710 of a surgical stapler 700 (see FIG.7). Additionally, inclusion of channels 410 a, 410 b helps reduce thefiring force necessary to properly form a staple and also helps biasstaple leg members 430, 440 to form in a certain direction.

With specific reference to FIG. 4B, surgical staple 400 is shown in adeformed orientation (configuration) and through a layer of tissue “t.”Specifically, first leg member 430 and second leg member 440 are shownin a deformed condition having a substantially curved shape and surgicalstaple 400 is shown in a B-like configuration.

Tissue penetrating portions 470 are shown formed adjacent a distal endof leg members 430, 440. Penetrating portions 470 may be of any knownconfiguration that facilitates entry of leg members 430, 440 into tissue“t” to be stapled. Tissue penetrating portions 470 are shown having achisel-like shape with points 472 adjacent inner facing sides of legmembers 430, 440.

Another embodiment of the present disclosure is illustrated in FIGS.5A-5B. Here, a surgical staple 500 includes a backspan 520, a first legmember 530, a second leg member 540 and two channels 510 a, 510 b. Firstleg member 530 and second leg member 540 each extend from backspan 520.In the illustrated embodiment, channels 510 a, 510 b (e.g., asubstantially continuous channels 510 a, 510 b) extend along an outersurface 560 of first leg member 530, backspan 520 and second leg member540. Inclusion of channels 510 a, 510 b helps facilitate proper firingand/or formation of surgical staple 500 upon contact with an anvilportion such as anvil portion 710 of a surgical stapler 700 (see FIG.7). Additionally, inclusion of channels 510 a, 510 b helps reduce thefiring force necessary to properly form a staple and also helps biasstaple leg members 530, 540 to form in a certain direction.

With specific reference to FIG. 5B, surgical staple 500 is shown in adeformed orientation (configuration) and partially through a layer oftissue “t.” Specifically, first leg member 530 and second leg member 540are shown in a deformed condition having a substantially curved shapeand surgical staple 500 is shown in a B-like configuration.

Tissue penetrating portions 570 are shown formed adjacent a distal endof leg members 530, 540. Penetrating portions 570 may be of any knownconfiguration that facilitates entry of leg members 530, 540 into tissue“t” to be stapled. Tissue penetrating portions 570 are shown having achisel-like shape with points 572 adjacent inner facing sides of legmembers 330, 340.

As can be appreciated, the transverse cross-sections of surgical staples400 and 500 are substantially identical (flipped vertically) and mayeach be formed from the same length of stock (not explicitlyillustrated).

In the illustrated embodiments, channel e.g., 110 is shown as beingsemi-circular and concave, however other shapes and orientations ofchannel 110 are envisioned. Alternatively, and as illustrated by thecross-section in FIG. 6, a rib 612 (e.g., a substantially continuousinternal rib or a substantially continuous external rib) or otherconvexity of surgical staple 600 may be positioned on the opposing sideof channel 614. Channel 614 is preferably proportional to or smallerthan the dimension of rib 612. Such rib or other convexity canoptionally be provided with the staples of the other embodimentsdisclosed herein.

Further, the size of channel 110 (applicable to the channels of thevarious staples disclosed herein) is shown as a particular size, but itis contemplated that channel 110 may be of any suitable size.Specifically, it is envisioned that a width “W” of channel 110 (see FIG.2C) may be between about 0.004 inches and about 0.007 inches and a depth“d” of channel 110 may be between about 0.001 inches and about 0.004inches. More particularly, width “W” may be between about 0.005 inchesand about 0.006 inches and depth “d” may be between about 0.002 inchesand about 0.003 inches. Alternatively, the dimensions of channel 110 maybe varied accordingly depending on the size and/or configuration of thestaple and its intended use.

Additionally, the dimensions of length of stock 50 used to make thevarious surgical staples disclosed herein are configured to further helpbias the staple leg members to form in a certain direction. That is,with reference to surgical staple 200 by way of example, staple 200includes a length dimension “L” (FIG. 1) greater than its heightdimension “H,” resulting in a moment of inertia ratio that favors properformation of surgical staple 200. That is, the force required toproperly form the staple is less than the force required to malform ortwist the staple. This is applicable to the other staples describedherein. More details of such moment of inertia ratios and relatedcalculations are disclosed in U.S. Pat. No. 7,398,907, the entirecontents of which are hereby incorporated by reference herein.

The various cross-sectional configurations of the surgical staplesillustrated in the figures may be achieved by any suitable methodincluding extrusion, rolling, coining, etc. or any reasonablecombination. Particularly, such configurations may be accomplished byflat rolling round wire stock on opposing sides and forming the channelor rib with a mandrel, extruder or form of a predetermined shape anddepth. In the fabrication process, stock 50 can be pre-rolled by thewire manufacturer or may be round wire stock which is rolled into thedesired cross-sectional configuration by the staple manufacturer.

As mentioned above, the channel(s) of the staples disclosed herein helpfacilitate proper firing and/or formation of the surgical staple uponcontact with the anvil portion such as anvil portion 710 of a surgicalstapler 700. The inclusion of the channel affects the cross-sectionalarea of portions of surgical staple and thus influences various momentsof inertia to minimize the likelihood of staple malformation. Thecross-sections can be uniform throughout the staple or can vary.

Turning to staples 200 and 300, and with particular reference to staple200, it being understood that the following is applicable to staple 300,the moment of inertia of cross-section of surgical staple 200 of FIGS.2A-2C is represented by I, with B representing a base of cross-sectionand H₁, H₂, and H₃ representing various heights of cross-section (seeFIG. 2C).

The moment of inertia, I, of the cross-sectional configuration of thesurgical staple 200 illustrated in FIGS. 2A-2C (single notched/channeledstaple) is given by the equation:

Moment of Inertia about Forming Axis

${Ixx} = {\int\limits_{vol}{{\rho\left( {y^{2} + z^{2}} \right)}{\mathbb{d}V}}}$

-   -   A staple cross-section with a single notch (channel) has by way        of example base dimension B=0.01075 in., a first height        H₁=0.00675 in., a second height H₂=0.00425 in., and a third        height H₃=0.00675 in.    -   therefore, the Area=5.609×10^(−0.05) in².    -   Accordingly, moment of inertia I_(xx)=1.63×10⁻¹⁰ in⁴.

The moment of inertia, I, of the cross-sectional configuration of thesurgical staple 400 (and staple 500) illustrated in FIGS. 4A-4C (doublenotched/channeled staple) is given by the equation:

Moment of Inertia about Forming Axis

${Ixx} = {\int\limits_{vol}{{\rho\left( {y^{2} + z^{2}} \right)}{\mathbb{d}V}}}$

-   -   A staple cross-section with 2 notches (channels) has by way of        example a base dimension B=0.01075 in., and a first and fourth        height H₁, H₄=0.00675 in., and a second and third height H₂,        H₃=0.00425 in.    -   therefore, the Area=5.572×10^(−0.05)    -   Accordingly, moment of inertia I_(xx)=1.44×10⁻¹⁰ in⁴.

The advantage of the channel (notch) can be appreciated by comparing itto the moment of inertia for a directionally biased staple which doesnot have any channels (notches):

Moment of Inertia About Forming Axis

${Ixx} = {\int\limits_{vol}{{\rho\left( {y^{2} + z^{2}} \right)}{\mathbb{d}V}}}$

-   -   A staple cross-section without a notch or rib that has a base        dimension B=0.01075 in., and a side height H=0.00675 in.    -   therefore, the Area=6.5907×10^(−0.05)    -   Accordingly, moment of inertia I_(xx)=2.29×10⁻¹⁰ in⁴.

Thus, as can be appreciated, less force is required to form the staplehaving one channel (notch) compared to the directional staple withoutany channels.

Since the surgical staple disclosed herein is forced through tissue “t”and the anvil and cartridge, e.g. anvil portion 710 and staple cartridge720, can flex as tissue is compressed and can move slightly relative toanother, the point of contact between staple leg points e.g. leg points272 of staple 200, and anvil portion 710 may be affected. For example,if anvil portion 710 moves slightly out of alignment, the staple legswill contact a different point of anvil portion 710 which can affectuniform formation of the surgical staple. Additionally, due tomanufacturing tolerances, the staple points 272 may not contact theanvil pockets in the exact optimal location. Although such stapleformation is clinically satisfactory and effective, the surgical staplesof the present disclosure may provide for more uniform formation and mayaccommodate greater manufacturing tolerances as they are more resistantto twisting. That is, the disclosed surgical staples will have thetendency to bend in the direction of the channel e.g., channel 210,which is desired because, here, the dimension of the surgical stapleincluding the channel defines the desired bending direction. By relaxingmanufacturing tolerances, the cost of manufacturing may be reduced aswell.

The present disclosure also relates to a surgical staple, such as thosedescribed above, for use with a surgical stapler such as endoscopicsurgical stapler 700 by way of example, shown in FIG. 7. Surgicalstapler 700 includes a staple cartridge 720 and anvil portion 710,including a plurality of pockets. Anvil portion 710 is spaced apart fromcartridge portion 720 such that staple cartridge 720 and anvil portion710 are configured to compress tissue “t” therebetween. The presentdisclosure further relates to staple cartridge 720 for use with surgicalstapler 700. Staple cartridge 720 includes a plurality of surgicalstaples, such as those described above, in a spaced relation to eachother. While a particular type of surgical stapler 700 is illustrated inFIG. 7, a staple cartridge of the present disclosure containing thestaples disclosed herein, preferably in linear or annular rows, may beused in connection with any suitable surgical stapler, including forexample open staplers and endoscopic staplers and circular or linearstaplers.

While the above description and accompanying figures illustrate thecross-sections of surgical staples of the disclosed embodiments having aparticular length and height, it is envisioned that surgical stapleshaving different cross-sections may also be utilized in connection withthe disclosed channel, channels or rib. For example, the presentdisclosure incorporates surgical staples having at least one channel orrib extending substantially continuously through at least the legmembers and having cross-sections where the length dimension is greaterthan the height dimension. The inclusion of at least one channel or ribwill further reduce the amount of force required to properly form astaple and/or help bias the staple leg members to form in a desiredorientation.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications of variousembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the claims appended hereto.

The invention claimed is:
 1. A surgical staple comprising: a linearbackspan; first and second leg members extending from the linearbackspan, each leg member of the first and second leg members includingan inner surface and an outer surface diametrically opposing the innersurface, the inner surface of the first leg member facing the innersurface of the second leg member; and at least one channel extendingalong at least one of an inner surface and an outer surface of thelinear backspan and at least one of the corresponding inner surface andouter surface of the first and second leg members, the at least onechannel being open along the entire length thereof, wherein each legmember of the first and second leg members includes a tissue penetratingportion including an angled surface configured to facilitate penetrationthereof through tissue.
 2. The surgical staple according to claim 1,wherein the at least one channel is semi-circular.
 3. The surgicalstaple according to claim 1, wherein at least one of the first or secondleg members includes a substantially uniform transverse cross-sectionalong its length.
 4. The surgical staple according to claim 1, wherein awidth of the at least one channel is between about 0.004 inches andabout 0.007 inches.
 5. The surgical staple according to claim 1, whereina depth of the at least one channel is between about 0.001 inches andabout 0.004 inches.
 6. The surgical staple according to claim 1, whereinthe surgical staple is formed from a material selected from the groupconsisting of titanium and stainless steel.
 7. A staple cartridgesupported on a surgical stapler, the staple cartridge comprising: aplurality of surgical staples in a spaced relation to each other, eachsurgical staple of the plurality of surgical staples including: a planarbackspan; a pair of deformable legs extending from the planar backspan,the pair of deformable legs configured to come into contact with anvilpockets of the surgical stapler for formation of a B-shaped surgicalstaple; and at least one open channel extending along at least one of aninner surface and an outer surface of each deformable leg and acorresponding surface of the planar backspan, wherein each leg of thepair of deformable legs includes a tissue penetrating portion having anangled surface configured to facilitate insertion through tissue.
 8. Thestaple cartridge according to claim 7, wherein the at least one openchannel is semi-circular.
 9. A surgical staple comprising: a backspandefining a plane; first and second leg members extending from thebackspan, the first and second leg members each including a firstsurface and a second surface diametrically opposing the first surface,the first surface of the first leg member facing the first surface ofthe second leg member, each leg member of the first and second legmembers including an angled tissue penetrating portion configured tofacilitate penetration through tissue; a channel extending along thebackspan and the first and second leg members, the channel being openalong the entire length thereof; and a rib extending along the backspanand the first and second leg members, the rib diametrically opposing thechannel.
 10. The surgical staple according to claim 9, wherein atransverse cross-section of each leg member of the first and second legmembers includes a length and a height, the height defined by a distancebetween a wall defining the channel and an opposing wall including therib, and the length being greater than the height.
 11. The surgicalstaple according to claim 9, wherein the first and second leg membersare substantially orthogonal to the plane of the backspan.
 12. Asurgical staple comprising: a backspan defining a plane; first andsecond leg members extending from the backspan, the first and second legmembers each including a first surface and a second surfacediametrically opposing the first surface, the first surface of the firstleg member facing the first surface of the second leg member, the firstand second leg members substantially orthogonal to the plane of thebackspan; a channel extending along the backspan and the first andsecond leg members, the channel being open along the entire lengththereof; and a rib extending along the backspan and the first and secondleg members, the rib diametrically opposing the channel.
 13. Thesurgical staple according to claim 12, wherein each leg member of thefirst and second leg members includes an angled tissue penetratingportion configured to facilitate penetration through tissue.